JKK High Pass Technical Studies Report

Controlling structure with wind

Technical studyInter 9Ja Kyung Kim

Chapter one. References _ Structure_a. Damper structure

Content

Structure_b. Wind turbine system

Structure_c. Ball joint structure

Chapter two. Project overview

Chapter three. Experimentations _ a. Damper structure

_ b. wind turbine structure

_ c. Ball Joint structure

_ Damper one _ Damper two

_Turbine system one _ Turbine system two

_Turbine system theree

_ Ball joint one _ Ball joint two

The tuned mass damper in the Taipei 101 skyscraper is a 660tonne steel sphere, made from flat circular plates welded together

For earthquake-prone countries in the developed world, there is no shortage of options for designing safer buildings. It’s actually a fairly marginal cost to make a building earthquake resistant — there’s no such thing as earthquake proof,’ said Main.Often used in California and Japan, where earthquakes of varying magnitudes are a frequent event, earthquake engineering makes buildings more resistant to ground shaking. There are two main ways to do this: either absorb the energy of the shaking within the building’s structure or decouple the main building structure from the ground so that the building moves much less when the ground begins to shake. Neither of these concepts are new. The Incas built cities such as Machu Picchu using dry-stone walls out of blocks cut to fit together. During an earthquake, the blocks could move slightly against each other, dissipating the energy of the quake and preventing resonant vibrations developing.

Read more: http://www.theengineer.co.uk/sectors/civil-and-structural/after-shock/1000838.article#ixzz1FXK9mAfH

The main tuned mass damper in Taipei 101 sits above the 87th floor

Decoupling the building from its foundation, which is known as base isolation, is possibly even older. Examples are known from more than 2,500 years ago in ancient Persia.Energy absorption techniques now reach their most spectacular in skyscrapers, which sway with a characteristic frequency during earthquakes. Massive pendulums are installed at the top of the tower, mounted on springs so they move in such a way as to counter the frequency of the swaying.Known as tuned mass damping, the technique is used in the Taipei 101 skyscraper in Taiwan, which, until last month, was the tallest building in the world. Taipei 101 has three tuned mass dampers; a 660-tonne, 5.5m-diameter steel sphere suspended between the 88th and 92nd floors; and two smaller dampers, each weighing 6 tonnes, at the top of the spire, more than 500m up.

Base isolation now generally involves connecting the building’s foundations to the building itself via shock absorbers. ’This was used in the reconstruction after the L’Aquila earthquake,’ said Main. ’The city built blocks of flats with a car park in the basement and the building itself is supported on isolation pillars.

’The pillars have shock absorbers on top with rubber components to absorb the vibration and a big concrete plate rests on top of the shock absorbers with the building itself on top of that,’ he added. ’There’s still some transfer of energy between the ground and the building, but it’s significantlyless than there would be otherwise.’

Read more: http://www.theengineer.co.uk/sectors/civil-and-structural/after-shock/1000838.article#ixzz1FXLtmX00

Chapter one. Reference _ Structure_a. Damper structure

Pole vaulting structure

Pole vaulting as an athletic activity dates back to the ancient Greeks. Modern competition started around the turn of the 20 th century, when the Olympic Games were restarted. A sharp increase in the achievable height coincided with the advent of composite (fibreglass) poles, about 50 years ago. These are sufficiently strong and flexible to allow substantial amounts of energy (kinetic energy of the athlete) to be transformed into elastic strain energy stored in the deformed pole, and subsequently transformed again into potential energy (height of the athlete) as the pole recovers elastically. The mechanics of beam bending is clearly integral to this operation.

The sharp increase in achievable height that coincided with the switch to composite poles was due to a change in the mechanics of pole vaulting. Bamboo or metal poles with sufficient flexibilityto allow significant energy storage would, respectively, be likely to fracture or plastically deform.

Visual inspection of a bent pole (see photo) is all that's needed to estimate the distribution of axial strains (and hence stresses) within its cross-section. The pole has a diameter of about 50 mm and it can be seen in the photo that it is being bent to a (uniform) radius of curvature, R , of the order of 1 m (~ length of the athlete's legs!). Considering a section of unit length (unstrained) in the diagram below, the angle θ (~tan θ ) ≈ 1/R after bending(where R is the radius of curvature). From the two similar triangles in the diagram, θ is also givenby the surface strain ε divided by r , the radius of the pole . The surface strain, ε, is thus given by the ratio r / R , which has a value here of about 2.5 %.

Chapter one. Reference _ Structure_a. Pole Vaulting structure

Tree branch structure

The structural system adopted here is that of a tree-branch. The propagation of the branching system along the longitudinal section of the conserved building is differentiated in its growth along the transverse section.

The tree structure was designed to be a steel truss and the challenge lay in working through the construction system compatible with local skills. Rather than looking at steel fabricators within the building construction sector, we sourced boiler fabricators for high precision work.

Chapter one. Reference _ Structure_a. Branch structure

Wind turbine skyscraper examples

Chapter one. Reference _ Structure_b. turbine structure

World trade centre in BahrainThe COR tower Castle house skyscraper

To find proper shape for the wind turbine system


Analysing of fan shape and movement


Looking at human joint

looking at how to connect each surface and make them stand upright, and thinking of the human muscle and joints helped me to generate form and system to connect the parts.

Chapter one. Reference _ Structure_c. Joint system

Study different way of using a ball joint system

Chapter one. Reference _ Structure_c. Joint system

Chapter three. Experimentations _ a. Damper structure

_ Damper one

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Process damper system

In the first step, different shapes were made as plain patterns into complex folded shapes.This means this infulences decrease and increase in the movement.

In the second step, a stick was prepared to make it rigid to surpport the top load. A 4mm aluminium stick was used. It was enough to test the system.

In the third step, created a bottom weight which had a round shape and I put sand in it.At this point, the quantity of sand was measured and controlled, depending on the top load.

In the last step, the same wind and speed direction were set up to get ready for the different shapes of the paper surface.

Different wind intensity

Different quantity of sand load

Different material of sticks

Different folded shape

45.86 29.34 17.53 14.28

Experimentation of the damper structure

Making the basic square paper and testing a different dynamic wind intensity.

A less shaking movement was created by the three plain surfaces but it still moved fast.

the basic shape of paper

4mm Aluminum

Sand

First step model

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Testing movement with different wind intensities

1234


42.31 21.14 10.00 8.95


Making one angled folded shape and testing a different dynamic wind intensity.

Third step model

One angled shape of paper

4mm Aluminum

Sand

1234


26.29 18.00 10.64 8.81

One folded shape of paper

4mm Aluminum

Sand

second step model


Making one vertical folded shape and testing a different dynamic wind intensity.

Fourth step model


Making differently angled folded shapes and testing a different dynamic wind intensity.

Differently angled folded shapes

4mm Aluminum

Sand

1234


35.93 25.83 23.22 14.06


Making a different load in the folded shape using thin metal sheets and testing a different dynamic wind intensity.


Making a differently length in the middle part of the structure and testing a different dynamic wind intensity.

Different load testing models

Different load _ Metal sheets

4mm Aluminum stick

Sand

Load _ paper

4mm Aluminum stick _ Doubled length

Sand

2X

Failure

In this experiment, the results failed completely because the loadwas extremely heavy so it lost the cetre of gravity. The doubled lengthof aluminium rod gave the funfamentally influenced my creation of the system.

Different movement of rotation

Different movement of rotation

Chapter three. Experimentations _ c. Damper structure

_ Damper two

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Weights

Water

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Process of the skyscraper system

One of my design strategy interests is huge heavy surface are placed on the top of structures and this makes different dynamic reflections with full sunlight. Moreover, the surface system works as a similar system to a wind turbine but it has different uses like creating new ways of reflection.As a starting point, I tried to look at wind turbine structures and different folding surfaces to control the movement to make it as slow as possible.

Process of making the skyscraper experimentations

Used a flexible wooden panel and placing different weights to test the same damper effect as with a skyscraper.

The first experimentation using different weights represented different loads on top, giving information about how the load affects movement as with high buildings.

Damper structure Movement structure Damper structure Movement structure

968g Weights

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1434g Weights 2100g Weights



The first experimentation using different weights represented different loads on top, giving information about how the load affects movement as with high buildings.

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The second experimentation using different amounts of water produced a suitable balance to make it stable.


Water _ 300g Water _ 600g

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The second experimentation using different amounts of water produced a suitable balance to make it stable.


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Used a flexible wooden panel and placing different weights to test the same damper effect as with a skyscraper. The third experimentation using both different weights and amounts of water increased the appropriate control point to find the balance. The reasons are the two points because of the greater weight and water movement helped to find the proper load.



4.5/7sec 3/7sec


Used a flexible wooden panel and placing different weights to test the same damper effect as with a skyscraper. The third experimentation using both different weights and amounts of water increased the appropriate control point to find the balance. The reasons are the two points because of the greater weight and water movement helped to find the proper load.



2/7sec 1/7sec

Chapter three. Experimentations _ b. Wind turbine structure

_ Turbine system one

Process of wind turbine system

Direction of wind

Folded surfaces as a fan

Load _ wooden base

4mm Aluminium stick

Testing of the wind turnbine system

Making the basic square paper shape and testing a different dynamic wind intensity.

A less shaking movement was created by the three plain surfaces but it still moved fast.

Wind Direction Rotations

Load _ a basic shape

4mm Aluminium stick

Load Testing the basic shaped paper

Rotations

Load

Wind Direction

Load _ one vertical folded shape

4mm Aluminium stick


Using one vertically folded shape with the same amount and directeion of dynamic wind intensity.

The vertical straight fold made more rotation than the first one because the shape got and held more wind to increase rotation. However I wanted like to make more complex shapes to increase rotation.

Testing one vertically folded shape


Load _ one angled folded shape

4mm Aluminium stick

Load Testing one angled folded shape


Using one angled folded shape with the same amount and direction of wind intensity.

This one angled folded surface gave a surprising result because it did not move as well.The one direction produced a plane kept which losing the wind direction and power because the wind slipped through the folded lines.


Load _ a differently angled shape

4mm Aluminium stick

Load


Making differently angled folded shapes and testing a different dynamic wind intensity.

The more complex triangular shape created more power to turn the planes because it caved in the middle. From this point, I could calculate how to increase and decrease the number of rotations. However, it needed more ways of defining how to control the power.

Testing differently angled folded shapes

Process of wind turbine system

Direction of wind

Different width of surfaces as a fan

Different number of surfaces as a fan

Reconfiguration of turbine system to recreate different reflection

Experimentation of the wind turbine system_ different widths and numbers of strips.

From this test, different arrangements of paper widths gave other ways of controlling the speed of rotation. The narrow surface decreased the speed but the wider surface made a faster rotation.

Experimentation _Three stripes _Thinner and thicker stripsDifferent paper strips created different degrees of rotation. Normally wind turbines contain three strips but four were tried to look at the differences.

20mm

50mm

Thinner strips

Thicker strips

Three strips with 50mm width

Three strips with 20mm width

Reconfiguration of turbine system to recreate different reflection

Experimentation of the wind turbine system_ different widths and numbers of strips.

From this test, different arrangements of paper widths gave other ways of controlling the speed of rotation. The narrow surface decreased the speed but the wider surface made a faster rotation.

Experimentation _ Four strips._ Thinner and thicker strips

20mm

50mm

Four strips with 50mm width

Four strips with 20mm width

Chapter three. Experimentations _ b. Wind turbine structure

_ Turbine system three

The main structure _ Surfaces Triangular meshes Configuration of wind turbine structure

Triangular meshes

Wind turbine system

Chapter 2

C_b. Triangle mesh frames and the wind system

Variations of different angled components

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a . Triangular frameb . Angled paper strips c . Movement of the windd . Direction of the fan

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Variations of different angled as folding meshes

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Chapter 2

C_a. Triangle mesh frames and the wind system

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Testing of triangular frame turn bine structure with 90 degrees

Triangle mesh frames and the wind system

Different sizes of paper shaspes were used because of the different proportions of the triangle frame. The shapes were folded in the same direction and shape but with different proportions and colours to create variations of coloured reflections

_ 90 degrees

90˚

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The about differently installation was placed at different angles _ 30 degrees

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Testing of triangular frame turbine structure with 30 degrees

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Variations of different angled components

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Variations of different angled as folding meshes

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Chapter 2

C_b. Triangle mesh frames and the wind system

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a . Triangular frameb . Angled paper strips with holes c . Detail of system to decrease wind forced . Direction of the fan

Triangle mesh frames and the wind system with holes on the surface

From the previous studies, the analyses of different variations in folding were not enough to adjust the system to slow it down.

Therefore, I started to investigate the actual surface to reduce the frictional force of the wind. Accordingly many holes were placed over the whole three surfaces to create the minimum friction. However it decreased the speed much less than expect.

Experimentation of triangle mesh frames and the wind system with holes

Experimentation of triangle mesh frames and the wind system with weights

a b c

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a b c

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a b c

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a b c

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Chapter three. Experimentations _ c. Ball joint structure

_ Ball joint one

Experimentation of free form of the ball joint system

It moves in different directions. It has 360 degree movement so it reveals different ways to investigate free form structure.

Ball

Elastic rubber thread

Direction of folding panel

Direction of movement


Testing of free form of the ball joint

Model of free form structure



Different stretched rubber thread

Different stretched rubber thread

Experimentation of one limited form of ball joint system

This moves in two different directions because the different lengths of elastic thread have an imbalanced stretch so this controls the movement. One direction is stretched fully so it is taut so the top panel doesn’t move freely in this direction.


Ball


Testing of one limited form of the ball joint

Model of one limited form structure



Experimentation of a controlled form of ball joint system

This moves to a certain degree and direction but till the rubber bands attached to the sphere make the ball stop when the top part meets the rubber bands.


Ball


Rubber bands

Testing of a controlled form of the ball joint

Model of a controlled form structure

Chapter three. Experimentations _ c. Ball joint structure

_ Ball joint two

A. Mesh frame

B. Ball joint

To create the joined mesh surface The mesh surface was joined with the ball joints. However it needed to be developed further to create the appropriate triangular surface with different reflection producing panels.

To join the meshThis system helps each surface to move and use the wind but it creates a big gap between them. It needed be closer to each other to form a new design strategy.

B B

AA A

Paper model Testing model

To create the joined mesh surface The mesh surface was joined with the ball joints. However it needed to be developed further to create the appropriate triangular surface with different reflection producing panels.

To join the meshThis system helps each surface to move and use the wind but it creates a big gap between them. It needed be closer to each other to form a new design strategy.

Horizontal movement Vertical movement

A. Mesh frame

B. Main hub

C. Ball joint

Testing model

A A

B C BC

To make the hub joint

The hub joint has an octagonal shape to create different angled joints. It indicates another possibility of creating the joint system.


To make the hub joint

The hub joint has an octagonal shape to create different angled joints. It indicates another possibility of creating the joint system.

A B

C C

A

B

A. Mesh frame

B. Turbine fans

C. Hub joint

B C

Making components and testing The part is a one part of the surface which is applied with the wind turbine system and the ball joint system all together. I folded and moved on to different directions to see the reaction of this structure. From this testing, I realised that it needed more density in the elastic on the ball joint to move in more controlled directions. Moreover the main hub needed a more specific shape or ways to adapt to what I aimed for with my space.

Testing model

Making components and testing The part is a one part of the surface which is applied with the wind turbine system and the ball joint system all together. I folded and moved on to different directions to see the reaction of this structure. From this testing, I realised that it needed more density in the elastic on the ball joint to move in more controlled directions. Moreover the main hub needed a more specific shape or ways to adapt to what I aimed for with my space.


Angled hub joints The hub joint was divided as 6 parts and these have the same shape and angle.So it could create different folded angles and shapes to create the new structure.However, I needed to know where it has to be placed for the structure, depending on the degree of folding angles. If the angle is plain, it needs a less angled hub joint but if it has a dynamic folding structure, it needs an extreme angled hub joint.

Besides, it is fixed on the bottom part structure, so it does not move as the other parts do.

Different variations of angled hub joints

Angled hub joints The hub joint was divided as 6 parts and these have the same shape and angle.So it could create different folded angles and shapes to create the new structure.However, I needed to know where it has to be placed for the structure, depending on the degree of folding angles. If the angle is plain, it needs a less angled hub joint but if it has a dynamic folding structure, it needs an extreme angled hub joint.

Besides, it is fixed on the bottom part structure, so it does not move as the other parts do.

Different variations of angled hub joints

Virtual testing of wind movements and direction on the site

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Virtual Columns

Smoke directions = wind directions

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Initial columns model for testing wind movement on the site Wind direction on the site

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Virtual testing of wind movements and direction with smoke

Tseting with smoke to see movements of wind direction among the columns. From this experimentation, I could see how wind hit the columns and make curve movements through the columns.Therefore, it can create a new form for my design spaces.

Testing wind different direction effect to the columns

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JKK High Pass Technical Studies Report